I am with you; as a project manager by trade I can relate to risk management quite well.
Assessing the most prominent risk an average household faces these days, the fridge, freezer and mobile phone come to mind… none of which are usually backed up by replacement hardware or alternatives.
Since light switches and even irrigation (if not used for production) do not fall into these high-risk categories,it supports my approach of not installing any light switches (for example).
What will certainly help is documentation of the systems, and quick guides for trades to understand the picture of how things work. E.g. for lighting: 240V > Power supply (240V/24V) > LED drivers (controlled by OH) > LEDs.
The idea of controllers assuming a default state has been implemented, and I will continue to do so. I use heartbeats via MQTT, which if not received by the respective device trigger either OFF or a default state.
However, I am looking at improving the fault-tolerance of my openHAB system… cluster, back-up, commercial network gear, etc.
And while I titled this post with “wall panel” in mind, which I pretty much solved with HABPanel, the LED wiring business still keeps me awake at night. I asked that question four years ago and still have not progressed, given the complexity of where to put the drivers (central vs close to the LED), wiring (DC vs AC)… The thikning here ATM is to wire everything back to a central space I have literally built for all things technical, network, electrical, OH, NAS, HRV, hot water, heated floor valves, pumps…
Keep the ideas coming; I appreciate it… as this forum is often the only ‘educated’ group I can run my ideas by; thank you. 